A bridge deck transition structure and construction method thereof

Abstract

The present invention belongs to the technical field of composite bridge deck structures, and in particular relates to a bridge deck transition structure and a construction method thereof. The transition structure changes the flat steel reinforcement into an inverted T-shaped reinforcement, adds vertical reinforcement below the inverted T-shaped reinforcement base plate, and forms a concrete slab steel support on the side of the steel-concrete composite beam. In order to improve the bonding capacity of the joint surface, prestressing, U-shaped reinforcement, tensile shear nails, and overlap between the ultra-high performance concrete layer and the concrete bridge deck are adopted to achieve a stable transition of the force transmission structure and stiffness. The present invention has the advantages of simple structure, convenient construction, firm and reliable joint surface, good durability and fatigue resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite bridge deck structures, and in particular relates to a transition structure between a bulb-flat steel reinforced lightweight composite bridge deck and a steel-concrete composite beam concrete bridge deck, and a construction method thereof. Background Art

[0002] Common stiffening rib types used in steel bridge decks include closed U-shaped ribs and open I-shaped ribs, T-shaped ribs, and bulb flats. U-shaped ribs offer greater stiffness, reducing secondary and tertiary stresses in steel bridge decks. They are most commonly used in long-span steel bridge decks, but they also suffer from drawbacks such as high steel consumption and difficulty in internal welding. Furthermore, they have numerous fatigue-prone details, making them more susceptible to cracking during operation. Traditional steel-concrete composite beams can address this problem, but their applicability is limited by their span.

[0003] In recent years, lightweight composite bridge deck structures have developed rapidly, with new bridge deck types, such as steel and ultra-high-performance concrete composite structures, gaining popularity. These types of bridge decks utilize the overlapping effect of steel deck panels and ultra-high-performance concrete layers to effectively increase deck stiffness and reduce deck stress. In this case, open-face panel reinforcement is more suitable, maintaining high deck stiffness while reducing steel usage, welding complexity, and further simplifying the structure. In open-face reinforcement, bulb flat steel offers a reasonable geometry and high material utilization, making it more suitable for long-span steel bridge deck structures. However, the cost of these composite bridge deck structures is higher than that of traditional steel-concrete composite beams.

[0004] On the other hand, multi-span bridges often employ a smaller side-to-midspan ratio due to factors such as topography, the environment, or economics. To balance the side-to-midspan loads and improve mechanical properties, while also considering cost-effectiveness, a lightweight composite structure can be used for the main span, while traditional steel-concrete composite beams and concrete decks can be used for the side spans. Structural systems employing this arrangement are rarely used in China, and ensuring their mechanical performance lies in developing a suitable deck transition structure. Currently, reliable technologies for this type of structure are lacking. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a combined bridge deck transition structure that is safe, reliable, reasonably stressed, and simple in structure.

[0006] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0007] A bridge deck transition structure is provided, wherein a cross beam at the interface between a light composite bridge deck reinforced with bulb flat steel and a concrete bridge deck reinforced with a steel-concrete composite beam is provided, an inverted T-shaped stiffening base plate is welded below the bulb flat steel stiffener in the transition structure, vertical stiffeners are added below the inverted T-shaped stiffening base plate, and a concrete slab steel support is formed on the side of the steel-concrete composite beam; prestressed steel bars are provided between the concrete bridge decks, the prestressed steel bars extend to the side of the light composite bridge deck, and are anchored between the stiffening plates under the prestressed anchors, and a cross beam at the tensioning end and a cross beam at the anchoring section are provided at the prestressed tensioning end and the anchoring section respectively, so as to improve the tensile strength of the interface; tensile U-shaped bars and tensile shear nails are provided at the connection between the cross beam at the interface and the concrete bridge deck, so as to ensure effective connection between the two bridge decks.

[0008] Furthermore, the lightweight composite bridge deck includes an ultra-high performance concrete layer, and the rigid surface layer below the ultra-high performance concrete layer has a thickness of less than 10 cm.

[0009] Furthermore, the steel-concrete composite beam concrete bridge deck is a composite structure of a steel structure and a concrete panel, the concrete panel is a prefabricated panel or a cast-in-place panel, and the steel structure is an integral box beam, a multi-piece box beam, a plate beam and a lattice beam.

[0010] Furthermore, the ultra-high performance concrete layer of the lightweight composite bridge deck should extend into the steel-concrete composite beam concrete bridge deck by 50 cm to 100 cm to achieve an effective transition of the force transmission structure and stiffness.

[0011] Furthermore, the concrete slab steel support below the inverted T-shaped stiffening base plate adopts a variable height shape along the force transmission direction, thereby achieving an effective transition of the stiffening plate force transmission structure and stiffness.

[0012] Furthermore, a welding hole is provided at the crossbeam at the reinforcement transition position, and the bulb flat steel reinforcement is continuous along the entire length of the crossbeam, which greatly improves the fatigue resistance of the welded node.

[0013] Furthermore, the bulb flat steel reinforcement and the concrete slab steel support thereunder are welded to the inverted T-shaped reinforcement base plate along the force transmission direction with a length of 50 cm to 100 cm, ensuring an effective transition of the force transmission structure and stiffness of the two reinforcement ribs.

[0014] Furthermore, the distance between the cross beam at the tensioning end and the cross beam at the anchoring end of the prestressed steel bar is 300cm to 400cm, forming a force transmission transition area of the concrete bridge deck.

[0015] Furthermore, an anchor stiffening plate is provided under the light composite bridge deck, and an anchor pad is provided around the anchor stiffening plate. The anchor stiffening plate and the steel top plate form a closed reinforcement to disperse the stress under the anchor and form a grouting space to improve the durability of the prestressed tendons; the prestressed steel bars are located inside the closed stiffening structure.

[0016] Preferably, the prestressed steel bars are prestressed steel strands, thick steel bars or parallel steel wire bundles.

[0017] The present invention has the following beneficial effects:

[0018] Compared with the existing technology, the present invention has a simple structure, clear force, and easy construction. It can effectively ensure the force and durability of the hybrid bridge deck. It uses multiple measures such as shear nails, U-shaped bars, extended longitudinal bars of ultra-high performance concrete layers, and prestressing to ensure the effective combination of the two bridge decks, thereby achieving a stable transition of force transmission structure and stiffness. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the elevation structure of a transition structure in a specific embodiment of the present invention;

[0020] Figure 2 It is a plan view along the AA direction of a specific embodiment of the present invention;

[0021] Figure 3 It is a cross-sectional view along the BB direction of a specific embodiment of the present invention;

[0022] Figure 4 It is a cross-sectional view along the CC direction of a specific embodiment of the present invention;

[0023] Figure 5 This is a partial enlarged view of area D of a specific embodiment of the present invention;

[0024] Figure 6 This is a partial enlarged view of region E of a specific embodiment of the present invention;

[0025] Figure 7 This is a partial enlarged view of a U-shaped rib in a specific embodiment of the present invention.

[0026] Numbers in the figure:

[0027] 1. Ultra-high performance concrete layer; 2. Concrete bridge deck; 3. Steel top plate; 4. Bulb flat steel reinforcement; 5. Inverted T-shaped stiffening web; 6. Inverted T-shaped stiffening bottom plate; 7. Concrete slab steel support; 8. Crossbeam at the joint surface; 9. Crossbeam at the tensioning end; 10. Crossbeam at the stiffening transition; 11. Tensile U-shaped reinforcement (at the joint surface); 12. Tensile shear nails (at the joint surface); 13. Prestressed steel bars; 14. Anchor pad; 15. Stiffening plate under the anchor; 16. Crossbeam at the anchor end. Specific implementation methods

[0028] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. In the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Among them, the drawings are only used for illustrative purposes and represent only schematic diagrams, not physical drawings, and cannot be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. For those skilled in the art, the omission of certain well-known structures and their descriptions in the drawings is understandable.

[0029] like Figure 1 、 Figure 2 As shown, the present invention is a transition structure between a light composite bridge deck reinforced with bulb-flat steel and a steel-concrete composite beam concrete bridge deck. The main components involved on the light composite bridge deck side are an ultra-high performance concrete layer 1, a steel top plate 3, and bulb-flat steel reinforcements 4; the main components involved on the steel-concrete composite beam side are a concrete bridge deck 2. The bulb-flat steel reinforcements 4 of the light composite bridge deck continuously pass through the reinforcement transition crossbeam 10 and are gradually welded to the inverted T-shaped reinforcement bottom plate 6. At the prestressed tensioning end, the crossbeam 9 transforms into inverted T-shaped reinforcements 5 and 6. A vertical reinforcement is welded below the bottom plate 6 to form a bridge deck support 7 on the steel-concrete composite beam side. A joint crossbeam 8 is provided at the interface between the two bridge decks. Please refer to Figure 6 The anchorage structure for the prestressed tendons on the lightweight composite bridge deck side ensures the performance of the interface. Prestressed steel bars 13 are used to preload the interface. Their tensioning end is located on the lightweight composite bridge deck side, with a prestressed tensioning end crossbeam 9 installed as the tensioning anchorage. Their anchoring end is located on the concrete deck side of the steel-concrete composite beam, with a prestressed anchoring end crossbeam 16 installed as the anchorage. To further enhance the tensile strength of the interface, U-shaped bars 11 and tensile studs 12 are welded to the crossbeam web at the interface. Furthermore, the ultra-high performance concrete layer 1 is extended 50-100 cm into the concrete deck.

[0030] The transition structure between the bulb-flat steel reinforced lightweight composite bridge deck and the steel-concrete composite beam concrete bridge deck in the above embodiment adopts the following construction steps:

[0031] Step 1: The factory manufactures the steel structure, including the longitudinal and transverse beam structures on both sides and the lightweight composite bridge deck side steel top plate, bulb flat steel and inverted T-shaped stiffening web and bottom plate;

[0032] Step 2: Install shear nails for steel-concrete composite beams, shear nails for light composite bridge decks, tensile shear nails at the interface, and weld U-shaped steel bars;

[0033] Step 3: Construct the concrete bridge deck on the side of the steel-concrete composite beam. When using cast-in-place bridge decks, prestressed steel pipes should be buried. When using prefabricated bridge decks, prestressed pipes should be reserved during bridge deck processing according to the design documents.

[0034] Step 4: Maintain the concrete bridge deck. When the strength meets the tensioning conditions, single-end tensioning of prestressed steel bars is performed on the lightweight composite bridge deck side. After tensioning, grouting is performed on the cavity formed by the anchor stiffener and the steel top plate.

[0035] Step 5: Pour the ultra-high performance concrete layer on the lightweight composite bridge deck side. Before pouring, the interface between the concrete bridge deck and the ultra-high performance concrete layer should be roughened to improve the shear resistance of the interface between the two materials.

[0036] Step 6: Maintain the ultra-high performance concrete layer and complete the construction of the transition structure between the entire lightweight composite bridge deck and the steel-concrete composite beam concrete bridge deck.

Claims

1. A bridge deck transition structure, characterized by: A cross beam (8) is provided at the interface between the light composite bridge deck reinforced by a bulb-flat steel and the concrete bridge deck reinforced by a steel-concrete composite beam. An inverted T-shaped stiffening base plate (6) is welded below the bulb-flat steel stiffening (4) in the transition structure. A vertical stiffening is added below the inverted T-shaped stiffening base plate (6) to form a concrete slab steel support (7) on the side of the steel-concrete composite beam. Prestressed steel bars (13) are provided between the concrete bridge decks (2). The prestressed steel bars (13) extend to the side of the light composite bridge deck and are anchored between the stiffening plates (15) under the prestressed anchors. A tensioning end cross beam (9) and an anchoring end cross beam (16) are provided at the prestressing tensioning end and the anchoring section, respectively. A tensile U-shaped bar (11) and a tensile shear nail (12) are provided at the connection between the cross beam (8) and the concrete bridge deck (2). The straight section at the tail of the U-shaped bar (11) is welded to both sides of the web of the cross beam (8) at the joint surface. An anchor stiffening plate (15) is provided under the light composite bridge deck, an anchor pad (14) is provided around the anchor stiffening plate (15), the anchor stiffening plate (15) and the steel top plate (3) form a closed stiffening structure, and the prestressed steel bars (13) are located inside the closed stiffening structure.

2. The bridge deck transition structure according to claim 1, characterized in that: The lightweight composite bridge deck comprises an ultra-high performance concrete layer (1), wherein the thickness of the rigid surface layer below the ultra-high performance concrete layer (1) is less than 10 cm.

3. The bridge deck transition structure according to claim 1, characterized in that: The steel-concrete composite beam concrete bridge deck is a composite structure comprising a steel structure and a concrete bridge deck (2), wherein the concrete bridge deck (2) is a prefabricated slab or a cast-in-place slab, and the steel structure is an integral box beam, a multi-piece box beam, a plate beam, or a lattice beam.

4. The bridge deck transition structure according to claim 1, characterized in that: The ultra-high performance concrete layer (1) of the lightweight composite bridge deck should extend 50cm to 100cm into the range of the steel-concrete composite beam concrete bridge deck.

5. The bridge deck transition structure according to claim 1, characterized in that: The concrete slab steel support (7) below the inverted T-shaped stiffening base plate (6) adopts a variable height shape along the force transmission direction.

6. The bridge deck transition structure according to claim 1, characterized in that: A crossbeam (10) at the reinforcement transition position is provided with a welding hole, and the bulb flat steel reinforcement (4) is continuous throughout the length of the crossbeam position.

7. The bridge deck transition structure according to claim 1, wherein: The flat steel reinforcement (4) and the concrete slab steel support (7) thereunder are welded to the inverted T-shaped reinforcement base plate (6) along the force transmission direction with a length of 50 cm to 100 cm.

8. The bridge deck transition structure according to claim 1, characterized in that: The distance between the cross beam (9) at the tensioning end of the prestressed steel bar and the cross beam (16) at the anchoring end is 300 cm to 400 cm.

9. The bridge deck transition structure according to claim 2, characterized in that: The prestressed steel bars (13) are prestressed steel strands, thick steel bars or parallel steel wire bundles.

10. The bridge deck transition structure according to claim 1, characterized in that: The transition construction method for a bulb-flat steel reinforced lightweight composite bridge deck and a steel-concrete composite beam concrete bridge deck comprises the following steps: S1: The steel structure is manufactured in the factory, including the longitudinal and transverse beam structures on both sides and the lightweight composite bridge deck side steel top plate, bulb flat steel and inverted T-shaped stiffening web and bottom plate; S2: Install shear nails for steel-concrete composite beams, shear nails for lightweight composite bridge decks, tensile shear nails at the interface, and weld U-shaped steel bars; S3: When constructing the concrete bridge deck on the side of the steel-concrete composite beam, if a cast-in-place bridge deck is used, prestressed steel pipes should be buried. If a prefabricated bridge deck is used, the prestressed pipes should be left during the bridge deck processing according to the design documents; S4: Curing the concrete bridge deck. When the strength meets the tensioning conditions, single-end tensioning of prestressed steel bars is performed on the lightweight composite bridge deck side. After tensioning, grouting is performed on the cavity formed by the anchor stiffener plate and the steel top plate. S5: Pour the ultra-high performance concrete layer on the lightweight composite bridge deck side. Before pouring, the bonding area between the concrete bridge deck and the ultra-high performance concrete layer should be roughened. S6: Maintain the ultra-high performance concrete layer and complete the construction of the transition structure between the entire lightweight composite bridge deck and the steel-concrete composite beam concrete bridge deck.

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